The purpose of the work is to locate and characterize fatty acid binding regions of human albumin. Fatty acid binding sites of albumin will be modified through affinity labeling with activated enol esters prepared from radioactive long chain fatty acids and Woodward's Reagent K. Samples of labeled albumins will be cleaved by chemical and/or enzymatic means to produce various peptide fragments. Fragments will be isolated by chromatographic and electrophoretic means and will be characterized by amino acid composition and sequence. Peptide segments which carry label will be assumed to have originated from a fatty acid binding site on albumin and their identification will identify the residues of albumin contributing to fatty acid binding sites. The distribution of fatty acid binding sites within the albumin molecule will be compared for atherosclerotic and non-atherosclerotic subjects.